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Sulfanilamide is a common antibacterial drug that is used in clinical practice and in the industry. However, its abuse has emerged as a serious problem in the aquaculture industry, and more predominantly in the poultry industry, where it is administered for therapeutic purposes or as a growth promoter. In this study, a novel technical platform, heat-assisted desorption-dielectric barrier discharge ionization mass spectrometry (HAD-DBDI-MS), was used to detect sulfanilamide in situ. A method for the rapid identification of five typical sulfanilamide drugs sulfamopyridine, sulfamethoxan, sulfamethoxoline, sulfamidine, and sulfamethoxazole was established after optimizing a series of parameters. Secondary mass spectrometry was used to distinguish the sulfanilamide drugs from one another and from other isomers. Our HAD-DBDI-MS method enhanced the sulfanilamide sensitivities by reducing the limits of detection by about 1-2 orders of magnitude compared to those obtained with the DBDI-MS method. check details As further research, the profiles of chicken feed with added sulfamopyridine standard as well those of commercial feed with added sulfamidine and sulfamethoxazole were obtained using HAD-DBDI-MS respectively. With the HAD-DBDI-MS method, sulfamopyridine could be directly detected in the complex chicken meat matrix. However, satisfactory results were not obtained when direct HAD-DBDI-MS was used for sulfamidine and sulfamethoxazole detection in the feed matrix. The identification ability was improved when methanol was introduced as the assisting solvent. In this method, chicken feed spiked with sulfamidine and sulfamethoxazole standards were pressed into tablets, and methanol was dropped on the tablet surface. The experimental data indicate that HAD-DBDI-MS is suitable for the rapid identification of sulfanilamide drugs in poultry feed and meat products, thus showing potential value as a detection tool for future application.A thermal desorption electrospray ionization-triple quadruple mass spectrometry (TD-ESI-MS/MS) method was developed for the rapid screening of poppy husk in hot pot sauce and soup. The solid surface or liquid sample was directly touched by a simple metal probe. The analytes collected on the probe were desorbed and ionized using a TD-ESI source, after which the analyte ions were detected by MS/MS in multiple reaction monitoring (MRM) mode. The results were compared with those of colloidal gold card rapid detection and verified by high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-MS/MS). The instrument gave the best response with the highest sensitivity under the following conditions thermal desorption temperature, 260 ℃; injection solvent, 0.1% formic acid aqueous solution containing 10 mmol/L formic ammonium-acetonitrile (11, v/v); flow rate, 200 μL/h. The limits of detection (LODs) for papaverine, noscapine, and thebaine in five alkaloids were 2 μg/kg, while those for codeine and morphine were 10 μg/kg in hot pot sauce and 5 μg/kg in soup. The sensitivity of this method was significantly superior to that of the colloidal gold card rapid detection. The method was applied to 50 batches of hot pot sauce and soup. Noscapine, papaverine, thebaine, and morphine were detected in a positive sample of chicken soup, which was consistent with the result of the HPLC-MS/MS method. This method without sample preparation and chromatographic separation is fast, green, and environmentally benign, thus being suitable for the rapid qualitative analysis of poppy husk in food.Gas chromatography (GC)-high-resolution mass spectrometry (HRMS) with accelerated solvent extraction (ASE)-purification simultaneously coupled to the isotope internal standard method is proposed for the determination of 32 polychlorinated biphenyls (PCBs) in aquatic products. Synchronous purification was achieved by adding 2 g of anhydrous sodium sulfate, 1 g of Cleanert Florisil, and 50 g of neutral alumina as the adsorbent to the ASE system. The PCBs were extracted from aquatic product samples using a dichloromethane-n-hexane (11, v/v) mixture at 100 ℃ with two extraction cycles. The extracting solution was purified twice with 0.5 mL concentrated sulfuric acid. After concentration to a constant volume, the target compounds were detected by GC-HRMS and quantified by the isotope internal standard method. Under the optimized conditions, the relative standard deviations (RSDs) of the mean relative response factor (RRF) for the 32 PCBs in the range of 0.1-20 μg/L were less than 15%. The limits of quantification were 0.3-1.9 ng/kg. At three spiked levels (5, 20, and 50 ng/kg) in grass carp and sea bass, the recoveries of the 32 PCBs were between 71.9% and 119.0%, with the RSDs varying from 3.5% to 19.6%. This method effectively reduces the matrix interference and shows high sensitivity, good reproducibility, and stable recovery, thus proving useful for the detection of PCBs in aquatic products.A method for the determination of vitamin K1 and vitamin K2 in modulation milk powder was developed by high performance liquid chromatography (HPLC) coupled with post-column reduction. The samples were dissolved in water, lipase hydrolyzed, saponified with 2.5 mol/L sodium hydroxide solution and ethanol solution, extracted with n-hexane, and dissolved in methanol after concentration. The vitamin K were first separated on an Xbridge C18 column and then on a zinc powder reduction column, and detected using a fluorescence detector. The excitation and emission wavelengths were 326 nm and 432 nm, respectively. An external standard method was used for quantification. The results showed that the linearities of vitamin K1 and vitamin K2 was in the ranges of 0.0025-2.0 μg/mL and 0.01-2.0 μg/mL, respectively, with correlation coefficients both greater than 0.999. The spiked recoveries were 80.39%-94.39% and the precisions were 0.85%-3.98%. The limits of detection of vitamin K1 and vitamin K2 were 0.07 μg/100 g and 0.2 μg/100 g, respectively. The limits of quantification of vitamin K1 and vitamin K2 were 0.2 μg/100 g and 0.8 μg/100 g, respectively. The method has high sensitivity and good repeatability, and gives accurate results. It is suitable for the analysis and determination of the vitamin K1 and vitamin K2 in formula milk powder.